218 
BATHYMETRICAL SURVEY OF 
north-west end, owing to the north-west winds prevailing during the 
time the Lake Survey was on the loch. For instance, on July 19 the 
temperature of the surface north-west of Hudh^ Aird an Anail was 
53°-9 at 3 p.m., and off Ardlair it was 54°*0 at 4 p.m., whilst at 
3.15 p.m. it was 55°’3 to the south-east of Fhasaigh. 
Five serial observations were taken on July 19 and 21, as given in 
the following table : — 
Depth 
in 
feet. 
Loch Maree, oppo- 
site Pool Crofts, 
July 19. 1902, 
12 noon. No 
wind. 
Loch Maree, S.W. 
of E. Ruairid 
M6r, July 19, 
1902, 6 p.m. 
Stiff N. breeze. 
Loch Maree, oppo- 
site Letterewe, 
July 21, 1902, 
12.45 p.m. 
Loch Maree, N. of 
E. Ruairid M6r, 
July 21, 1902, 
1 p.m. Light 
N.W. breeze. 
Loch Maree, off 
Rndh’ a’ Ghui- 
bhais, July 21, 
1902. 6 p.m. 
Moderate N.W. 
wind. 
o 
o 
o 
o 
o 
o 
0 
53-5 
54-7 
53-9 
53-9 
53-9 
54-5 
5 
IJ 
53-8 
54-2 
4 
10 
536 
53-7 
53-7 
54-2 
15 
53 6 
54-7 
53-5 
53-3 
53-4 
20 
53-5 
54-2 
25 
54-0 
53-5 
53-7 
30 
53-6 
53-3 
54-0 
35 
53-2 
50 
53 0 
53T 
53 0 
54-0 
75 
50-0 
50-8 
50-3 
53-6 
80 
85 
49-6 
100 
48 -0 
49-0 
48-2 
48-0 
150 
48T 
46-9 
46-6 
46-4 
2(X) 
47 0 
45-9 
46-0 
45-9 
250 
45-4 
300 
45*6 
350 
45-5 
Below the surface the fall in temperature was slow down to about 
50 feet, when the fall became very rapid down to 150 feet, and then 
slow again to the bottom. Though these are the characteristics of the 
three series taken on the 21st, that taken on the 19th to the south of 
Eilean Ruairid Mor in the Slattadale basin does not agree with the 
others. In this case there was a rapid fall from 20 to 100 feet, and 
then a slight rise in temperature to 150 feet, and then a slow fall again 
to 200 feet. 
The series taken to the north of Eilean Buairid Mor on the 21st is 
interesting on account of the decided inversion at 25 feet. Though 
these inversions of temperature have occasionally been observed, they 
are by no means common. In this case it was noticed that the tempera- 
ture fell from 53°*9 at the surface to 53°*7 at 10 feet, and to 53°*3 at 15 
feet, and then rose to 53°'5 at 25 feet, and then fell again steadily below 
this depth. The series down to 25 feet was repeated with the results 
shown in the second column under this head, which proved that the 
inversion, though small, was real and not due to the instrument. 
